Recording paper and recording apparatus using same

ABSTRACT

A recording paper including a color varying layer which normally exhibits a predetermined color and a substrate layer having a color different from that of the color varying layer, wherein the predetermined color disappears when a beam of specific wavelength is incident thereon.

This application is a continuation of application Ser. No. 08/230,112,filed Apr. 20, 1994, now abandoned, which is a continuation of07/934,403, Aug. 24, 1992, now U.S. Pat. No. 5,329,300.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording paper on which an image,such as letters, can be directly recorded by beam scanning. Theinvention further relates to a recording apparatus, such as a printer orcopier, etc., for recording information on the recording paper.

2. Description of Related Art

It is known to use a coloring agent having a predetermined color whichdisappears when a specific wavelength is made incident thereon as acopying toner. Namely, if the coloring agent is used as a copying toner,information recorded on a copying paper is erased when the copying paperreceives a beam of specific wavelength incident thereon, therebyrestoring the copying paper so that it may be reused. An articleentitled "Trends" in "NIKKEI MECHANICAL" dated Jul. 22, 1991 disclosessuch a toner.

The known coloring agent is made of a mixture of IR820B which is a bluecyanine dye and ammonium salt of organic boron compound. When awavelength of 820 nm (near-infrared radiation) is incident on thecoloring agent, the blue color disappears, so that the coloring agentbecomes transparent. It is assumed that this phenomenon occurs due to anirreversible reaction which occurs when the IR820B absorbs thewavelength of 820 nm in the presence of ammonium salt of organic boroncompound, which functions as a catalyst.

However, the applicability of such a coloring agent has been limited toa copying toner to make copying papers reusable. Namely, theconventional concept of the application of the coloring agent isaddressed only to reusable copying paper.

In a conventional laser printer, a laser beam is on-off modulated inaccordance with printing data output from a computer to form a latentimage on a photosensitive drum. The latent image is then transferred tothe recording paper through a toner. This type of laser printer isaccordingly complex.

Furthermore, in a conventional copying machine, an image is formed on aphotosensitive drum by light reflected from an original document(manuscript, etc.) to be copied and the image is then transferred to therecording paper through a toner, again, resulting in a complexconstruction.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a recordingpaper on which an image, such as a letter, can be directly recorded ordrawn using the above-mentioned type of coloring agent and laser beam.

A further object of the present invention is to provide a recordingapparatus which can easily record information on the recording paper.

Still a further object of the present invention is to provide a simpleprinter and copier using the recording paper.

According to the present invention, there is provided a recording papercomprising a color varying layer which normally exhibits a predeterminedcolor, but which color disappears when a specific wavelength is incidentthereon, and a substrate layer having a color different from that of thecolor varying layer.

With this structure, an image, such as a letter or figure, can bedirectly formed on the recording paper by beam scanning. Namely, sinceonly the portions of the color varying layer on which the laser beam ofspecific wavelength is incident become transparent, the color of thesubstrate layer appears to obtain a desired image. The beam scanningtechnology is per se known in a conventional printer or copier, etc.Accordingly, a desired image can be easily recorded on recording paperby using the image recording system in which the special recording paperproposed in the present invention is used.

Preferably, the color varying layer is made of a mixture of IR820B (atype of cyanine dye) and ammonium salt of organic boron compound. Thespecific wavelength is near-infrared 820 nm.

The present invention is also directed to a printer and a copier inwhich the recording paper, according to the present invention, is usedto make possible the direct recording of a desired image by beamscanning.

Consequently, it is not necessary to provide a photosensitive body(photosensitive drum) which transfers information (i.e., an image) to becopied or printed on recording paper in a copier or printer of thepresent invention.

To this end, a printer according to the present invention comprises arecording paper which includes a color varying layer exhibiting apredetermined color in a normal state, however, the color of whichdisappears when a laser beam of specific wavelength is incident thereon.The printer further comprises a substrate layer having a color differentfrom that of the color varying layer, a paper feeding mechanism whichfeeds the recording paper, a light source which emits a laser beamhaving a specific wavelength, and a beam scanner which modulates thelaser beam in accordance with predetermined printing data and scans therecording paper while the paper is being fed by the paper feedingmechanism.

In the printer described above, an information transferringphotosensitive drum, a toner supplier, and a fixing device, etc., areall unnecessary, thereby allowing for the realization of a simpleprinter.

According to another aspect of the present invention, a copying machine,in which the recording paper specified above is used, comprises a beamscanner which optically scans a manuscript to be copied with the laserbeam, a paper feeding mechanism which feeds the recording paper at aspeed synchronous with the scanning speed of the beam scanner, and animage forming optical system which converges light reflected from themanuscript onto the moving recording paper.

With this printer, a photosensitive drum which is used to transfer theimage of the manuscript thereto, a toner supplier, and a fixing device,etc., are all unnecessary, resulting in the realization of a simplecopier, similar to the printer as mentioned above.

The recording paper, according to the present invention, can be usedinstead of a recording paper for a conventional diazo copier (bluecopy). In this case, a light source which emits a specific wavelength isused along with a paper feeding mechanism which feeds a recording papersuperimposed on a transparency, so that the recording paper receives thespecific wavelength incident thereon at portions other than themanuscript of the transparency. A developing device which wasindispensable in the conventional diazo copier can be omitted.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below in detail with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic view of a recording paper according to a firstembodiment of the present invention;

FIG. 2 is a schematic view of a recording paper according to a secondembodiment of the present invention;

FIG. 3 is an enlarged schematic view of a transparent capsule whichconstitutes a color varying layer of a recording paper shown in FIG. 2;

FIG. 4 is a schematic view of a recording paper according to a thirdembodiment of the present invention;

FIG. 5 is a schematic view of a recording paper according to a fourthembodiment of the present invention;

FIG. 6 is a schematic sectional view of a printer using a recordingpaper according to the present invention;

FIG. 7 is a developed plan view of a printer illustrated in FIG. 6;

FIG. 8 is a schematic sectional view of a copier using a recording paperaccording to the present invention; and,

FIG. 9 is a schematic sectional view of a copier using a recording paperaccording to another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a first embodiment of a recording paper according to thepresent invention. In FIG. 1, a recording paper 10 has a substrate layer(base) 11 and a color varying layer 12 provided on the substrate layer11. The color varying layer 12 is made of a paint 12c having a mixtureof IR820B grains (cyanine dye) 12a and ammonium salt grains of organicboron compound 12b. The color varying layer 12 normally exhibits a bluecolor from the IR820B grains 12a.

The ammonium salt of organic compound 12b is comprised of, for example,tetrabutylammonium butylphenylborate. The chemical formula of IR 820B isshown below. These materials are shown in an article entitled "Trends"in "NIKKEI MECHANICAL" dated Jul. 22, 1991. ##STR1##

    Ph.sub.3 B.sup.- [N(-.sub.n C.sub.4 H.sub.9).sub.4 ]+

The base 11 exhibits a color other than blue. The color of base 11 ispreferably selected from those having a high contrast with respect toblue. However, a color having a low contrast with respect to blue, suchas black, etc. may be used.

FIGS. 2 and 3 show another embodiment of the present invention, in whichthe Grains 12a of IR820B (cyanine dye) and grains 12b of ammonium saltof organic boron compound are contained in transparent capsules 12dwhich are adhered to the substrate 11 by paint 12c.

FIG. 4 shows a third embodiment of the present invention, in which anintermediate layer (undercoat) 13 is additionally provided between thesubstrate layer 11 and the color varying layer 12.

In a fourth embodiment of the present invention, FIG. 5 shows atransparent protection layer 14 additionally provided on the colorvarying layer 12.

When recording paper 10, as constructed above, is scanned with a beam820 nm in wavelength (near-infrared radiation) only the portions of thecolor varying layer 12 receiving the incident beam become transparent,so that a desired image (letters, figures, etc.,) appear having a colorof the substrate 11 or the intermediate layer 13.

A beam scanning technology which is per se known, for example, in aprinter or a copying machine, etc., can be employed to obtain a desiredimage in the present invention.

Recording paper 10, on which the image (information) has been recorded,can be reused after illuminating the entire color varying layer 12 withlight 820 nm in wavelength, so that the entire color varying layer 12becomes transparent, the remaining color of the paper being identical tothat of the substrate 11 or the undercoat 13.

As can be seen from the above discussion, a recording paper on which adesired image (letters, figures, etc.) can be formed by making light ofspecific wavelength incident thereon can be obtained. Consequently, aprinter or copier can be simplified by the use of a recording paper ofthe present invention.

FIGS. 6 and 7 show an embodiment of a printer according to the presentinvention in which the recording paper 10 mentioned above is used.

The 820 nm laser beam emitted from a laser source (laser diode) 21 ismade incident upon an on-off modulator 24 through a mirror 22 and acondenser lens 23. The laser beam is on-off modulated by the on-offmodulator 24 in accordance with printing data stored in a computer 25.The modulated laser beam is then collimated by a collimating lens 26 andmade incident upon a rotatable polygonal mirror 29 through mirrors 27and 28. The laser beam reflected by reflecting surfaces 29a of thepolygonal mirror 29 is converged onto the recording paper 10 which isfed by a paper feeding mechanism 33 through an f θ lens 30 and a mirror31.

The paper feeding mechanism 33 which is known per se includes a feedingroller 33a and a transparent glass 33b through which the laser beam istransmitted. The recording papers 10 are accommodated in a paper feedingtray 34 and are discharged therefrom by a paper discharging roller 35.The recording paper 10 fed by the paper feeding mechanism 33 movesunderneath the transparent glass 33b. The speed at which the recordingpaper 10 is fed is synchronous with the rotational speed of thepolygonal mirror 29, so that when the 820 nm laser beam, which is on-offmodulated in accordance with the printing data, is incident upon therecording paper 10 while the paper is being moved, portions of the colorvarying layer 12 of the recording paper 10 that receive the laser beambecome transparent. As a result, only the color of the base 11 or theundercoat 13 appears at the portions thereof corresponding to thetransparent portions of the color varying layer 12. Thus, a directprinting can be effected. It should be appreciated that no furtherprocess, such as a development or fixation, etc., is needed thereafter.

The used recording paper 10 can be used as a color paper having a coloridentical to that of the substrate 11 or the undercoat 13 byilluminating the entire color varying layer 12 of the used recordingpaper with light of 820 nm, so that the entire color varying layer 12becomes transparent. As can be understood from the above discussion,according to the present invention, a specific wavelength, which ison-off modulated in accordance with predetermined printing data, isdirectly made incident on the recording paper on which a desired imagecan be formed by the incident specific wavelength. Accordingly, an imagetransferring photosensitive drum, a toner, a developing device, and afixing device, etc., which were all necessary in the conventionalprinter can be dispensed with, resulting in the realization of a simpleand inexpensive printer.

FIG. 8 shows an embodiment of a copying machine in which the recordingpaper 10 is used, according to the present invention.

In FIG. 8, a beam scanner 42 is provided below a manuscript supportingglass plate 41 on which a manuscript O (original document) is to becopied. As is well known, the beam scanner 42, which is identical tothat in a known copier, includes a full speed unit 43 which moves in adirection parallel with the plane of the glass plate 41 and a half speedunit 44 which moves in the same direction at a speed half the speed ofthe full speed unit 43. The full speed unit 43 is provided with a lightsource 45 which emits light of 820 nm (near infrared radiation) and amirror 46. The half speed unit 44 is provided with a pair of mirrors 47and 48.

Light emitted from the light source 45 is reflected by the manuscript Oon the glass plate 41, and is then reflected by the mirrors 46, 47, and48 to be made incident upon an image forming lens system 50. The imageforming lens system 50 together with an immovable mirror 51 constitutesan image forming optical system which converges the light reflected fromthe manuscript O directly onto the recording paper 10, fed by the paperfeeder 33, to form an image. The paper feeder 33 is identical to that ofthe printer shown in FIG. 6. Namely, the paper feeder 33 includes afeeding roller 33a and a transparent glass 33b through which the lightreflected by the manuscript O is transmitted.

The recording paper 10 which is accommodated in the feeding tray 34 aredischarged therefrom by a paper discharging roller 35. The recordingpaper 10, fed by the paper feeding mechanism 33, moves underneath thetransparent glass 33b. The speed at which the recording paper 10 is fedis synchronous with the scanning speed of the beam scanner 42, so thatwhen light reflected by the manuscript O is incident upon the recordingpaper 10, through the image forming lens system 50 and the immovablemirror 51, an image corresponding to the black and white pattern of themanuscript O is formed on the recording paper 10. Namely, portions ofthe color varying layer 12 of recording paper 10 that receive thereflected light become transparent. As a result, only the color of base11 or undercoat 13 appears at the portions thereof corresponding to thetransparent portions of the color varying layer 12. Thus, a directrecording can be effected. It should be appreciated that no furtherprocess, such as a development or fixation, etc., is needed.

A lens having a fixed focal length can be used as the image forming lenssystem 50 in an equi-magnification (constant magnification) type copierand a zoom lens can be used in a variable magnification type copier.

FIG. 9 shows another embodiment of a copier according to the presentinvention. A copier illustrated in FIG. 9 can be used in place of anexisting diazo copier. In FIG. 9, the light source 60 emits light of 820nm wavelength. The paper feeder 61 has a paper feeding roller 61a and atransparent glass 61b, similar to the embodiment illustrated in FIG. 8.The recording paper 10 and the transparent manuscript O superimposedthereon are fed between the paper feeding roller 61a and the transparentglass 61b at a predetermined speed. During the movement of the recordingpaper 10 and the transparent manuscript O, light emitted from the lightsource 60 is made incident upon the recording paper 10 by the condenserlens 62 through the manuscript O.

In the modified embodiment illustrated in FIG. 9, a black and whiteimage pattern of the manuscript O is recorded on the recording paper 10.Again, neither development nor fixation are needed after recording.

Recording paper 10 can be reused after illuminating the entire colorvarying layer 12 of the used recording paper with light of 820 nm, sothat the whole color varying layer 12 becomes transparent leaving theremaining paper with a color identical to that of the substrate 11 orthe undercoat 13, similar to the above-mentioned embodiment applied to aprinter.

As can be seen from the above discussion, according to the presentinvention, since light reflected by the manuscript is directly madeincident on the recording paper, on which a desired image can be formedby a specific wavelength incident thereon, an image transferringphotosensitive drum, a toner, a developing device, and a fixing device,etc., which were all necessary in a conventional copier, can bedispensed with, resulting in the realization of a simple and inexpensivecopier.

Having thus described the invention, what is claimed is:
 1. A recordingpaper having on a recording surface thereof a first layer and a secondlayer overlying and blocking said first layer, said first layer beingcolored a first color and said second layer being of a second colordifferent from said first color, said second layer being opaque to saidfirst layer and formed of a compound that becomes transparent to saidfirst layer when said second layer is exposed to a beam of light of aspecific wavelength.
 2. A recording layer in accordance with claim 1wherein the color varying layer is made up of a mixture of a cyanine dyein accordance with the following formula ##STR2## and ammonium salt oforganic boron compound.
 3. A recording paper according to claim 2,wherein the specific wavelength is a near-infrared beam.
 4. A recordingpaper according to claim 3, wherein the specific wavelength is 820 nm.5. A recording paper in accordance with claim 1 wherein said first colorand second color are contrasting.
 6. A recording paper in accordancewith claim 1 wherein said first layer comprises a surface of saidrecording paper.
 7. A recording paper in accordance with claim 1 furthercomprising a permanently transparent protective layer overlying saidsecond layer.